More than 98% of cocoa butter is simple lipid. More than 95% of this is triacylglycerol. Free fatty acid values are reported to be 1.5% and the concentration of mono- and diacylglycerol is about 2% of the simple lipid fraction.
Cocoa butter contains a high proportion of saturated fats, derived from stearic and palmitic acids. It exhibits a very complex crystallization system as a result of the different glycerides present. It is polymorphic, which means it will crystallize in several different forms according to how the liquid fat is solidified.
It generally acts as the continuous phase in chocolate, supporting the nonfat ingredients.
Thus, the properties of the chocolate – relatively hard and brittle at room temperature yet melting rapidly in the mouth – are greatly dependent on the properties of the cocoa butter itself. It is light yellow fat, exhibiting a distinct brittle fracture below 20 °C, a fairly sharp complete melting point about 35 °C with an incipient fusion or softening around 30-32 °C.
Cocoa butter
